Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

Motorcycle break in tips. There are lots of different opinions on how to break your engine in.

Here's a brief explanation
It has been pointed out that every motorcycle model Kawasaki makes comes with the same, 4000 RPM initial break-in limit sticker on the tach. This really isn't fair, because of gearing. Some bikes do 50 mph or more in top gear at 4000 rpm, while the Ninja 250 only does 35 mph, so the bike that does 50 mph in top gear will consume 500 miles sooner. It's really backwards, because EX250 works harder, and would break itself in sooner than, say, a 2-liter, 5k RPM-redline Kawasaki Vulcan. But a mindful break-in is still important.

This is a much-debated topic; some say baby it, some say ride it like you stole it. I'm just going to put up my take on the matter, backed up with a few empirical items.

The fact is that an engine is not fully broken for several thousands of miles. During that period, you have to respect it more than you would a fully broken in engine. That said, the Ninja 250 is probably 95% broken in by 500 miles. And it's probably 90% broken in by 50 miles. Still -- and this is really beside the point of this article -- the engine is not fully broken in until 5000 miles or so, when everything in the engine is completely seated, at which point the engine begins to ever-so-slowly deteriorate (just like you grow until you're 27 years old, then you start to die).

Now, what does "respecting the engine" mean? Generally, it's all about friction and lubrication. Until the engine is run in, there is more friction and less lubrication on critical parts (valves, cams, rings, bearings, etc). These parts must be in good shape for the engine to run efficiently and for long periods of time. Exceed the proper RPMs, and the unworn components will get too hot too fast; you will get hardened rings, scored cylinders, and valves that do not seat correctly. This may not make a huge difference at first, but the increased wear will encourage more advanced wear. Loss of compression, noisy bearings, leaking seals... the list is extensive. But it adds up to less power and shorter engine life span in the long run.

So again: What is the proper respect? What are the proper RPMs? This is a matter of much disagreement. But here is what is usually agreed upon: Do not mess with an engine until it is fully heated up, fully lubricated and ready to be pushed. No one will disagree that multiple, progressive heat cycles are a Good ThingTM, and that frequent oil changes early can never hurt.

Is there a formula for all this? Not exactly, but here's a good method I would use: make the engine work harder the more you break it in, always keeping the temperature and friction inside in mind.


Here's an example from Duke, who competed in the 2005 Iron Butt Rally on an EX250 he built for the purpose of competing:

Here's the details of the break-in of my rally bike. This motor was basically brand-new - then re-built from scratch with minor oil flow and valve seat modifications. It completed 9,500 miles during the Iron Butt Rally in Aug./Sept. 2005. The motor was started for the first time in March 2005. As of January 2006, it has 22,000 miles.

NOTE - complete cooldown between each run (at least 4 hours). Used Castrol GTX 10W-40.

* Initial Startup Idle 10 minutes Coolant to full temperature.
* Ride #1 5 miles 5-8k Spinning motor w/ no load
* Ride #2 8 miles 5-10k Short medium loading
* Ride #3 12 miles 5k-12k-5k Short loading (Wide Open Throttle) / Engine braking
* Ride #4 15 miles 5k-14k-5k Short loading (WOT) / Engine braking
* Ride #5 20 miles 5k-14k-5k Short loading (WOT) / Engine braking

Oil/filter change

* Ride #6 22 miles 8k-14.5k-8k Short loading (WOT) / Engine braking
* Ride #7 38 miles 8k-14k-8k Short loading (WOT) / Engine braking
* Ride #8 15 miles 5k-12k Commute to work on Interstate - Vary RPMs
* Ride #9 15 miles 5k-12k Commute to work on Interstate - Vary RPMs
* Ride #10 15 miles 5k-12k Commute to work on Interstate - Vary RPM
* More commuting up to just over 500 miles

Oil/Filter change

* 768 miles Nashville, TN to Omaha, NE - Interstate - Ride as normal
* 768 miles Omaha, NE to Nashville, TN - Interstate - Ride as normal

It then went on the 48-hour MD-20/20 Rally - Covering just over 2,000 miles during the 48 hours. In July it went 5,100 miles in 4 days, 22 hours. It had 10,000 miles on it at the beginning of the IBR in late August. Changed to Rotella 5W-40 Synthetic at 5k, just before the 5-day ride. 10K at the start of the IBR. I felt the motor began to feel 'broken-in' between 7-9k miles.

This is the strongest Ninja250 I've personally ridden. The amount of oil it burned during the IBR varied from none to about 1/4 qt. per 1,000 miles.
(source: http://faq.ninja250.org/wiki/Do_I_really_have_to_follow_this_break-in_period%3F)

This is an example of HARD Break-in method.
Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

Disclaimer: There's a lot of controversy an objection on this kind of break in method.The directions given on this site WILL contradict your manufacturers' instructions. If you decide to do it, do it at your own risk, and if you screw your engine up don't come about suing me.



Here's another one:
http://www.ntnoa.org/enginebreakin.htm